Intasol Combi Diverter Valve
Links a solar-heated unvented cylinder to a combi boiler, so stored solar water goes to the taps when it is hot enough, and into the combi as a pre-heat when it is not.
What it does
The valve sits between a solar-heated unvented hot water cylinder and a combi boiler. If the cylinder drops below a usable temperature, it diverts that water to the combi and treats it as incoming pre-heat. It then blends water from the combi, or from the cylinder, with mains cold so the outlet is a safe temperature for the taps.
The Hub review of this setup puts the changeover at 48°C. At 48°C or above, cylinder water goes straight to the taps at a set temperature. Below 48°C, the water is sent to the combi at about 28°C and brought up to the combi’s hot-water setpoint, instead of the combi heating from cold. Either path then goes through a thermostatic mixing valve before the taps.
Features
- Links a solar-heated unvented cylinder to a combi boiler
- WRAS approved
- Diverts to the combi when the cylinder temperature is low
- Uses the solar-heated water in the cylinder first
- Blends the outlet to a usable hot-water temperature
- Maximum static pressure 10 bar
- Maximum dynamic pressure 5 bar
- Temperature adjustment 35–55°C, stability ±2°C
- Maximum inlet temperature 110°C
- Minimum flow for stable operation 6 l/min
The same Hub note put the valve at about £300. That figure is from 2018, so check a current supplier price before specifying it. The point of the valve is to use solar-heated water when the cylinder can supply it, and to avoid heating the combi from cold when it cannot.
Guidance from the original Hub product page. Fitting and unvented work need a qualified engineer. See also solar thermal heating.